405 line recording.

[ppppenguin]

Well worth trying a B&W mode if one is available.

Slightly OT, I've got a couple of older VHS machines hanging around doing nothing. AFAIK they both work but I haven't tried them for several years. They are Fergy Videostars, clunky push button electronic controls. Not sure which model but they're the right sort of age to be OK with 405. £10 each or £15 the pair but I really wouldn't want to pack and ship them. Collection from North London or some kind of arrangment if a kind person is headed in the right direction.

[peter_scott]

Originally Posted by channel405

The tape differences shouldn't make a difference, I think this is a playback phenomenon rather than a recording issue.

Tim

Hi Tim,

Again, I haven't looked to see how SVHS differs but the recording is certainly different because an ordinary VHS machine can't play SVHS tapes. I think you'll find that your SVHS machine will sense whether or not to record in SVHS mode by the hole pattern on the cassette base.

Peter.

[channel405]

Hi Peter

Yes thats right about the hole in the cassette activating the switch between both recording formats. SVHS machines are backwards compatible with VHS. The main difference is wider FM deviation for higher Y bandwidth (about 400 lines instead of 240) and wider for chroma. Y and C are kept apart through the whole signal processing hence the seperate connections. The pic quality is only slighlty better though because noise remains quite high despite denser tapes (metal?) and drum/tape speed is still quite low compared to Beta SP etc. Still its good enough for 405 lines, apart from the ghosting thing of course!

Tim

[oldeurope]

Originally Posted by channel405

Hi Peter and all,

Daruis, thanks for your suggestion about the back porch with Umatic recordings. But if I remember the original 405 spec didn't include a porch before the H pulse, and as the camera I used is of 1966 vintage I don't know if the camera would be generating one.
Tim

Hi, I am born in the same year as your camera.
In the british standard it is 0.5us before the H-pulse begins and app. 5us
after the end of the H-pulse.
You can see it on the oscilloscope. But from your pics this is not your
problem. Vision in the flyback looks different.

Darius

[oldeurope]

Originally Posted by peter_scott

Hi Tim,

Again, I haven't looked to see how SVHS differs but the recording is certainly different because an ordinary VHS machine can't play SVHS tapes. I think you'll find that your SVHS machine will sense whether or not to record in SVHS mode by the hole pattern on the cassette base.

Peter.

Hi Peter, drill a hole in your standard VHS-tape and try to make recordings.
If you have a good tape you'll get success and save money hi hi.

Darius

[Heatercathodeshort]

Hello,
I have checked the speed of the video head on both 405 and 625 and you are correct, it is the same and of course must be! I had checked it visually at first and by the sound of the head. It never fails to amaze how you can convince yourself of the impossible! I ended up sticking a small square of reflective tape onto the drum and using the head off a truck tacho tester proved that they were the same. The garage guys thought I had gone off my rocker....The two readings were identical but were in MPH rather than RPM. Thanks for putting me right on this issue. Regards JOHN.

[channel405]

Hi Darius,

Yes you are of course quite right about the presence and duration of the porch on the 405 waveform, I have just consulted my 1949 "Priciples of (405 Line) Televsion". I was sure that there was something like a porch that 405 never used but 525 and 625 did, could I be thinking of equalising pulses? Or am I just talking jiberish?!

I must point however the pics are from a VHS tape were kindly recoreded for me and not from the Sony 405 camera. The camera footage is on a Umatic tape and I will get a pic of that as soon as I locate the tape.

Tim